/**
 *    Copyright (C) 2014 10gen Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
 *    as published by the Free Software Foundation.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU Affero General Public License for more details.
 *
 *    You should have received a copy of the GNU Affero General Public License
 *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *    As a special exception, the copyright holders give permission to link the
 *    code of portions of this program with the OpenSSL library under certain
 *    conditions as described in each individual source file and distribute
 *    linked combinations including the program with the OpenSSL library. You
 *    must comply with the GNU Affero General Public License in all respects for
 *    all of the code used other than as permitted herein. If you modify file(s)
 *    with this exception, you may extend this exception to your version of the
 *    file(s), but you are not obligated to do so. If you do not wish to do so,
 *    delete this exception statement from your version. If you delete this
 *    exception statement from all source files in the program, then also delete
 *    it in the license file.
 */

#pragma once

#include <boost/scoped_ptr.hpp>
#include <vector>

#include "mongo/db/geo/s2.h"
#include "third_party/s2/s2cap.h"
#include "third_party/s2/s2cell.h"
#include "third_party/s2/s2loop.h"
#include "third_party/s2/s2polygon.h"
#include "third_party/s2/s2polyline.h"
#include "third_party/s2/s2region.h"

namespace mongo {

    // Simple GeoJSON polygon with a custom CRS identifier as having a strict winding order.
    // The winding order will determine unambiguously the inside/outside of the polygon even
    // if larger than one hemisphere.
    //
    // BigSimplePolygon uses S2Loop internally, which follows a left-foot rule (inside to the
    // left when walking the edge of the polygon, counter-clockwise)
    class BigSimplePolygon : public S2Region {
    public:

        BigSimplePolygon();

        BigSimplePolygon(S2Loop* loop);

        virtual ~BigSimplePolygon();

        void Init(S2Loop* loop);

        double GetArea() const;

        bool Contains(const S2Polygon& polygon) const;

        bool Contains(const S2Polyline& line) const;

        // Needs to be this way for S2 compatibility
        bool Contains(S2Point const& point) const;

        bool Intersects(const S2Polygon& polygon) const;

        bool Intersects(const S2Polyline& line) const;

        bool Intersects(S2Point const& point) const;

        // Only used in tests
        void Invert();

        const S2Polygon& GetPolygonBorder() const;

        const S2Polyline& GetLineBorder() const;

        //
        // S2Region interface
        //

        BigSimplePolygon* Clone() const;

        S2Cap GetCapBound() const;

        S2LatLngRect GetRectBound() const;

        bool Contains(S2Cell const& cell) const;

        bool MayIntersect(S2Cell const& cell) const;

        bool VirtualContainsPoint(S2Point const& p) const;

        void Encode(Encoder* const encoder) const;

        bool Decode(Decoder* const decoder);

        bool DecodeWithinScope(Decoder* const decoder);

    private:

        boost::scoped_ptr<S2Loop> _loop;

        // Cache whether the loop area is at most 2*Pi (the area of hemisphere).
        //
        // S2 guarantees that any loop in a valid (normalized) polygon, no matter a hole
        // or a shell, has to be less than 2*Pi. So if the loop is normalized, it's the same
        // with the border polygon, otherwise, the border polygon is its complement.
        bool _isNormalized;

        // Cached to do Intersects() and Contains() with S2Polylines.
        mutable boost::scoped_ptr<S2Polyline> _borderLine;
        mutable boost::scoped_ptr<S2Polygon> _borderPoly;
    };

}

